Healthcare Chapter: Vital Signs

Vital Signs

• Vital signs are body temperature, pulse, respiration, and blood pressure.
• Pain is now considered a fifth vital sign.
• Vital signs assess the physiological functioning of the body. They include body temperature, pulse, respirations, blood pressure, pain, and pulse oximetry.

When to Check Vital Signs

• On admission to a healthcare agency to establish a baseline.
• When a patient's health status changes or reports symptoms (e.g., chest pain, feeling hot).
• Before and after surgery or invasive procedures.
• Before or after medication administration that could affect the respiratory or cardiovascular systems.
• Before and after any nursing intervention that might affect vital signs (e.g., ambulating a patient).

Body Temperature

• Body temperature is the balance between the heat produced by the body and the heat lost from the body.
• It's measured in degrees.
• Core temperature of deep tissues (thorax, abdomen, pelvis) remains relatively constant at 37°C (98.6°F).
• Surface temperature of skin, subcutaneous tissue, and fat changes based on the environment.

Factors Affecting Body Heat Production

• Basal metabolic rate: The rate of energy use for essential activities (e.g., breathing). Metabolic rate decreases with age, with younger individuals having higher rates.
• Muscle activity: Muscles produce heat through the breakdown of substances.
• Fever: Increases cellular metabolic rate and body temperature.
• Thyroid hormone output: Hormones like thyroxine and triiodothyronine increase basal metabolism by breaking down glucose.

Heat Loss

• Most heat is lost from the skin's surface through:
  • Radiation: Emission of heat waves when body temperature is higher than the surroundings.
  • Conduction: Direct heat transfer through contact with a cooler object.
  • Convection: Heat loss via moving air currents (e.g., fans).
  • Evaporation: Heat loss through the evaporation of water (e.g., sweating).

Normal Body Temperature

• For ages 5 to adult: 36°C to 37.5°C (96.8°F to 99.5°F) axillary.
• For newborn to 1 year: 36.8°C (axillary).
• For older adults: 36°C (axillary).

Factors Affecting Body Temperature

• Age: Infants are susceptible to environmental temperature changes and need protection. Older adults (over 75) are at risk for hypothermia.
• Diurnal variations: Body temperature fluctuates throughout the day, typically highest in the late afternoon/evening and lowest around early morning.
• Exercise: Increases body temperature.
• Hormones: Women typically experience more hormonal fluctuations than men; progesterone levels affect temperature around ovulation.
• Stress: Increases the production of stress hormones that raise metabolic activity and body temperature.
• Environment: Changes in environmental temperatures can impact a person's temperature regulation system.

Temperature Ranges

• Afebrile (Normal): Normal body temperature.
• Pyrexia (Fever): 37.5°C to 39.5°C (99.5°F to 103.1°F)
• Hyperpyrexia: Above 40°C (104°F)

Clinical Signs of Fever

• Increased heart rate and respiratory rate.
• Shivering.
• Cold skin.
• Complaints of feeling cold.
• Cyanotic nail beds.
• "Goose flesh" appearance of skin.
• Cessation of sweating.

Nursing Interventions for Hyperthermia

• Monitor vital signs.
• Assess skin color and temperature.
• Monitor white blood cell count and other lab results for infections or dehydration.
• Remove excess blankets.
• Provide adequate nutrition and fluids.
• Measure intake and output.
• Reduce physical activity.
• Administer antipyretics as prescribed.
• Provide oral hygiene.

People at Risk for Hyperthermia

• People with infections.
• People with central nervous system disorders that affect thermoregulation.

Hypothermia

• Core body temperature is below normal range.

Clinical Signs of Hypothermia

• Decreased body temperature, pulse, and respiration.
• Severe shivering.
• Feeling of cold and chills.
• Pale, cool, waxy skin.
• Hypotension.
• Decreased urinary output.
• Disorientation.
• Drowsiness progressing to coma.

Nursing Interventions for Hypothermia

• Provide a warm environment.
• Provide dry clothing.
• Apply warm blankets.
• Keep limbs close to the body.
• Cover the head with a cap or turban.

Patients at Risk for Hypothermia

• Those participating in cold-weather sports.
• Elderly individuals with inadequate food, clothing, or shelter.
• Individuals with neurological deficits who cannot respond to cold.
• Individuals with extreme heat loss, like alcoholics experiencing vasodilation.

Sites for Measuring Temperature

• Oral: Mouth. Contraindications: Infants/young children, unconscious/confused patients, recent facial/mouth/neck surgery/injury, oxygen use >6L/min, paralysis or seizure disorder
• Axillary: Armpit. Indications: patients who mouth-breathe, have oral inflammation, or recent oral surgery, oral or rectal temperature not indicated.
• Rectal: Rectum. Indications: Infants, young children, unconscious patients, mouth-breathing patients
• Aural: Ear canal.
• Temporal artery: Forehead.
• Tympanic: Ear drum.

Types of Thermometers

• Mercury thermometers
• Electronic thermometers (sensitive tape, electronic, infrared, forehead).